/* 
 * From Unix Network Programming Volume 1, by Ruchard Stevens
 * Define functions related with error processing 
 */
#include	"networking.h"

#include	<stdarg.h>		/* ANSI C header file */
#include	<syslog.h>		/* for syslog() */

int		daemon_proc;		/* set nonzero by daemon_init() */

static void	err_doit(int, int, const char *, va_list);

/* Nonfatal error related to a system call.
 * Print a message and return. */

void
err_ret(const char *fmt, ...)
{
  va_list		ap;

  va_start(ap, fmt);
  err_doit(1, LOG_INFO, fmt, ap);
  va_end(ap);
  return;
}

/* Fatal error related to a system call.
 * Print a message and terminate. */

void
err_sys(const char *fmt, ...)
{
  va_list		ap;

  va_start(ap, fmt);
  err_doit(1, LOG_ERR, fmt, ap);
  va_end(ap);
  exit(1);
}

/* Fatal error related to a system call.
 * Print a message, dump core, and terminate. */

void
err_dump(const char *fmt, ...)
{
  va_list		ap;

  va_start(ap, fmt);
  err_doit(1, LOG_ERR, fmt, ap);
  va_end(ap);
  abort();		/* dump core and terminate */
  exit(1);		/* shouldn't get here */
}

/* Nonfatal error unrelated to a system call.
 * Print a message and return. */

void
err_msg(const char *fmt, ...)
{
  va_list		ap;
	
  va_start(ap, fmt);
  err_doit(0, LOG_INFO, fmt, ap);
  va_end(ap);
  return;
}

/* Fatal error unrelated to a system call.
 * Print a message and terminate. */

void
err_quit(const char *fmt, ...)
{
  va_list		ap;

  va_start(ap, fmt);
  err_doit(0, LOG_ERR, fmt, ap);
  va_end(ap);
  exit(1);
}

/* Print a message and return to caller.
 * Caller specifies "errnoflag" and "level". */

static void
err_doit(int errnoflag, int level, const char *fmt, va_list ap)
{
  int		errno_save, n;
  char	        buf[MAXLINE];
  
  errno_save = errno;		/* value caller might want printed */
  vsnprintf(buf, sizeof(buf), fmt, ap);	/* this is safe */
  n = strlen(buf);
  if (errnoflag)
    snprintf(buf+n, sizeof(buf)-n, ": %s", strerror(errno_save));
  strcat(buf, "\n");
  
  if (daemon_proc) {
    syslog(level, buf);
  } else {
    fflush(stdout);		/* in case stdout and stderr are the same */
    fputs(buf, stderr);
    fflush(stderr);
  }
  return;
}
